Mariem Smaoui

Design and energy control of stand-alone hybrid wind/photovoltaic/fuel cell power system supplying a desalination unit

Faced with increasing trend of water demand and decreasing resources of fossil fuels and their high costs, desalination units based on renewable energies have become the best solution to face this challenge. This paper aims to investigate the design and the operation strategy of stand-alone hybrid renewable power generation system supplying a desalination unit which feeds the Kerkennah islands (Tunisia) with fresh water. The sizing of all the main hybrid system components such as photovoltaic generator, wind turbine, a fuel cell, and an electrolyzer is investigated in order to obtain some technical and economic profitability. In order to ensure the optimal use of the produced energy and satisfy the fresh water needs, a novel power management algorithm that allows controlling the energy flows within the system components is developed. Simulation results were carried out over the two months of January and July, and its results are shown in our paper. These results demonstrate the feasibility and the efficie...

Prevalence of factor V Leiden in south Tunisian blood donors.

Venous thrombosis (VT) is a common disease with multifactorial pathogenesis. Factor V Leiden mutation (G1691A) (FVL) is the most common risk factor in venous thrombosis. The prevalence of FVL varies according to geography and ethnicity. Hence, in several countries there is a difference in the frequency of this mutation between the southern, central and north. In Tunisia, no data is available about prevalence of FVL mutation by geographical origin. For this reason, we sought the prevalence of FVL mutation in blood donor of south Tunisia population. FVL has been detected by APCR-test and confirmed by PCR-RFLP and sequencing. Two hundred fifty blood donors, different in age and sex were included in this study to determine the prevalence of FVL in blood donors. FVL mutation was found in 13.6% of the studied population. Thirty-one were heterozygous and three persons were homozygous with a rate of 12.4 and 1.2%, respectively. In conclusion, FVL mutation is very common in south Tunisian population.

Sizing of a stand-alone hybrid system supplying a desalination unit

Economic and environmental concerns over fossil fuels encourage the development of renewable energy. But to allow the penetration of intermittent energy sources, optimal sizing of hybrid renewable energy systems is quite necessary. This paper presents an optimal sizing algorithm which estimates the sizes of different components of hybrid photovoltaic/wind power generation system supplying a desalination unit. The optimal combination of the hybrid system is selected according to its technical and economic profitability. A case study is conducted to analyze a hybrid project, which is designed to supply a desalination unit feeding the Kerkennah islands (Tunisia) with fresh water.

Allelic polymorphisms of human platelets-specific alloantigens in South Tunisian population

Abstract Objectives Human platelet-specific alloantigens (HPA) are polymorphic epitopes which vary among ethnic groups. Background In Tunisia, HPA frequencies were determined in North and centre; however, the pattern of HPA in South Tunisian population is not been studied yet. The aim of this work was to determine allelic frequencies of HPA-1, -3, and -5 systems in south Tunisian population, in order to estimate the risk of anti-platelet allo-immunization and to create a register of HPA-typed blood donors. Methods Our study concerned 212 unrelated healthy, regular blood donors from southern Tunisia. Allelic polymorphisms of each system were determined using a polymerase chain reaction with sequence-specific primers. Results Genotype frequencies a/a, a/b, and b/b were, respectively, 0.670, 0.288, and 0.042 for HPA-1 system, 0.430, 0.462, and 0.108 for HPA-3 system, and 0.750, 0.241, and 0.009 for HPA-5 system. The allele frequencies were 0.814 and 0.186 for HPA-1a and -1b alleles; 0.660 and 0.340 for HPA-3a and -3b alleles and 0.870, and 0.130 for HPA-5a and -5b alleles. Discussion The reported frequencies are more similar to those of Caucasians than those of north Tunisian population.

Culture-independent genome sequencing of Coxiella burnetii from a native heart valve of a Tunisian patient with severe infective endocarditis

We report draft genome of a Coxiella burnetii strain sequenced from the native valve of a patient presenting with severe endocarditis in Tunisia. The genome could be sequenced without a cellular or axenic culture step. The MST5 strain was demonstrated to be closely related to the published reference genome of C. burnetii CbuK_Q154.

Graphical interface development of a sizing algorithm of a photovoltaic/wind/hydrogen system

This paper presents a simulation graphical interface of a sizing algorithm of a hybrid renewable energy system. This algorithm has been developed for sizing the components of a stand-alone PV/wind/hydrogen system supplying a desalination unit which feeds the Kerkennah islands (Tunisia) with fresh water. The aim of this approach is to determine, among a list of commercially available system devices, all possible configurations of the hybrid system that would guarantee a reliable energy supply. The simulation and the display of all configurations obtained by this algorithm are performed by the graphical interface. This interface sorts the obtained combinations according to their investment cost in ascending order, selects the optimal solution and presents the various curves describing the behavior of the optimal hybrid system.

A new power ma nagement algorithm for a stand-alone hybrid system supplying a desalination unit

A renewable hybrid system coupled to a reverse osmosis desalination unit in southern Tunisia is studied. The hybrid system includes a photovoltaic generator, a wind turbine, a fuel cell and an electrolyzer. To allow a real penetration of intermittent energy sources and to satisfy the fresh water needs, a new power management algorithm allowing the control of the energy flow between the system components is developed. Two sub-algorithms are incorporated in this algorithm. These two sub-algorithms identify the production lines number operating at a pre-defined time interval and adjust the consumed power by the desalination unit. Simulation results are carried out over one year and present the different parameters describing the behavior of the system. These results demonstrate the feasibility and the efficiency of the used control strategy and the performance of the hybrid system.

Modeling and control of a desalination unit based solar energy

The power of desalination system by renewable energy sources (RES) systems has been going through an upwards trend, especially during the last decade. This paper concerns the modeling and the control of a desalination unit by reverse osmosis based solar energy. The system includes photovoltaic panels, electrical converters, batteries and a desalination unit which presents the load. Dynamic modeling of various components of this isolated system is presented. To ensure the balance between consumption and production and to guarantee the proper operating of the unit, control loops are developed. The simulation results show that the proposed hybrid power system equipped with control loops operates efficiently under load power demand variations.